"one obstinate in asserting or adhering to his own opinions," c. 1600, from French opiniastre, from Latin opinio "opinion, conjecture" (see opinion) + deprecatory suffix (see -aster). Another word in a similar sense was opinator "opinionated person" (1620s), from Latin opinator "one who supposes or conjectures." Also opiniator (1520s).
"a petty poet, a feeble rhymster, a writer of indifferent verses," 1590s, from French poetastre (1550s), from Latin poeta (see poet) + French-derived -aster, a diminutive (pejorative) suffix. Old Norse had skaldfifl in roughly the same sense. Early modern English had rimester (1580s). Swinburne (1872) used poeticule. Related: Poetastry.
Proto-Indo-European root meaning "star." Buck and others doubt the old suggestion that it is a borrowing from Akkadian istar "venus." The source of the common Balto-Slavic word for "star" (Lithuanian žvaigždė, Old Church Slavonic zvezda, Polish gwiazda, Russian zvezda) is not explained.
It forms all or part of: aster; asterisk; asterism; asteroid; astral; astro-; astrobiology; astrobleme; astrognosy; astroid; astrolabe; astrolatry; astrology; astromancy; astronaut; astronomy; AstroTurf; constellation; disaster; Estella; Esther; instellation; interstellar; lodestar; star; stardust; starfish; starlet; starlight; starry; stellar; stellate.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit star-; Hittite shittar, Greek aster "star," with derivative astron; Latin stella, Breton sterenn, Welsh seren "star."